Heat exchange system



Aug. 27, 1935. R OLSON 2,012,728

HEAT EXCHANGE SYSTEM Filed Jan. 16, 1934 2 Sheets-Sheet l sea/E9970? jUPPLY INVENTOR amoNDE. OLSON BYE-WW ATTORNEY Aug. 27, 1935.

R. E. OLSON 2,012,728 HEAT EXCHANGE SYSTEM Filed Jan. 16, 1954 2 Sheets-Sheet 2 7 0 VQLVE L9 70 Ale SUPPLY Leak BY AW ATTORNEY Patented Aug. 27; 1935 Tayloiri Instr ment 'QQmI wi S; R h t temqand: moreiparticularlyztoi a; method of 'and toahpparatusafor controlling the temperature of a. liquid; heated. in a, heat-exchange-system. 1 1' vI'riiflo'netype of heat exchange systemdt has beenproposedr to maintain aspredetermined tlemr pereture -0fthe liquid at the outletof the system, inwspite of.:changes inthe rate of. fiow 'there- *through or wide variations inethe temperature of the'iiquidlenteringthe heater, by varying the amount' ef heaLtintr-oduced into the system in response: to variations" in said outlet temperar- T It lies also been prop osed to heet'ailiquid in a, heat exchange system to a. predetermined temperature by supplying afixed amou-ntof heat to the'liq'uidbeing heated arid varying the rate of flow of' -th'e liq'uid through the system mustard -a,rice= withthe temperature of this 'liquid after it is e'ated; =by regulatii1g the speedof the pump for rowing mne' liqum through the system.- In

V suc a r-1 arrengem'el t -wher e the speedofthe fiumb is varied in; accordance withthtefriiiera} ture -th'e outgoing liquid; elaborate cdntr'ol mechenisjr'ri'is' required'but in spite er su'eh meshfir'iism; the resulting centrol oi the temperature aceerdagricewiththe presrit'invention, a. efrhethogi of heitiiig' a iiqui'q. a. heater toe. Y edeterrr iined. temperature; is pre'ilided in which affixewaimqunt pf -hatis sup li'd w the'i-iqu-id while arying the rate dfflbwf of t e liquidto the heater' 'from; a {source of the ligu idf urirler a. "substantiallyuniform heed pr pressure. Spe cificaily the; ihventieh'relates to a, [milk heater 61 the type iuwhich a fixed em ount pf *heat is sf; plied" thereto, and which a milk 'pump 'in the@fi'iiik supply pipe td the heater is operated at a. predetrmiried fixeld' spee1tp-suppiy ir1i1k predeterminedpressure te a co'r'i'duit lead. jim g tb Said.- l ie ater, 's'a1id" conduit having; a; walve 'th ereinfthe Qpening' -oi lQSiI-IQOQf effeeted to 'vary the rate 'qf miik 'flQWfi-Il accord.-

' 'th the temziersiture of the "heated milk, ture ofthemilk discharged J i ini .7 Thes'eand. ether features or the invention will abpepr from the detailed fdescription aiidelaims Mien taken with the kiraiwin'gs -in' whioh e1 is a. 1 diagrammatic -showing of a. J milk pasteuriz- 'in'g -syetin according to the present invention whrein the 'miik heaiter ior pasteurizer is shown -fiartialiy' -sectiong Fig. =52: is a' diagrammatic shewing ofiapmecording regulatorzmhichuincludes -equipment tor controlling the opening and 1010smail-1.1.5 l-"236 2 A'This'invention relates-to aheat ex {change eyepum 1? th eueh 1}? mm- M nd t ec il iti we stopp d-wh never the milk dis ha ed 19m t l :heater is be ow-the pr d rm ped",temn ratumi ffi.

a d F gs. 3, 4 d .57 re deta sect o al Vi w 9 a valve in the milk supply pipe: leading the heater, File 4 heme a sect n tak n on he 44 of Fig. 3 and Fig. 5 being? seetiqr taken on the-l ne .5 a o s-" w R f r n snec a l to F le, .5 ind yates {A rectan u a mi heat r PQV F HI W 70 t??? t pe hav ng two e Q$ d arb n Pl es 91' 9mg ele t od s 6 nd 7 m u te i he W k the e? 'Iheseelec mdesa e ectrica l i l lat pl' i m i ea h 't er ut a e r sp cti e neete Y c duct s and 9& 5 1 9 I uni o m WP rent, ot-shown. it is unnecessary to'gie'scr;

u ther th "cqnvst u t t f th e erlh xcei ae beams-thus sup d to the mi es wgz r the:

h qugh, V W n. hivs e swmfmi k imm he y wi k fl ws ughpipe I I into the ur k Hei u eerme enera i imam 5-01 t 9ni il9 r ee i r and 990, 2 F m the r en a e thee; Maw betw e the e t $1 and '1 of the heater where it is hetedgnqi. fleyvs i mneueh t eg ehar e p et t -k e m;

' w ch s he es the i k mean -mi1 1g;flows \over the quts ide qf the coilsiof the 1k is mp 1. it amete-tunnel 1. tqmthis fumed t iw i fi 9 sensitive element orbulb 21 in the discharge out 7 let 2|;of the heater. The valve [9 has an expansible diaphragm 'top or expansible chamber [Haoperating on the application of pressure fluid thereto; toj m'ove the valve stem lSb toward the valve-closingiposition against the action of a springl9c which tends to maintain the valve open-The details of this valve are further shown in Figs. 3, 4 and 5.; :The valve stem l9b is illustrated as carrying a valve disc 'l 9d which, 1 as'best shown in'Fig. 4,=has a notch I 96' cut in its side so that it permits a small amount of milk to flow therethrough, even when the valve is fully closed. The valv'e'disc I911 cooperates with a plug element l9 mounted inithe valvebody which element has a V-shaped port [9g therein, so that the area of the port uncovered 'by the valvedisc is proportional to the move- ;ment of the disc. I

The regulating device-apart from the valve l9 includes the thermo-sensitive bulb 21 which communicatesfthroug'h a conduit 35 and a branched conduit 36 with the Bourdon spring 31. This sp'ring,-' in turn, controls the operation of the regulating valve I9 and also'moves a pen arm46 andits stylus 48 to make a record of the temperature of. the heated milk on achart ,49, as will be more fully set'forth hereafter. Conduit 35 also communicates through the branch conduit 38 with a' capsular diaphragm or 'metal bellows 39. This'bellows by ,means'of'valve 4| controls the Ioperation of 'the 'bellows 43 which; in turn, effects the closure: of contacts 44 inthe men'tioned'cirfcuitbf motor 26; The bulb 21, theBourdon "spring 31 and the capsular diaphragm 39, as well as-fiche. mentioned conduits, constitute, whatis 'jkn in the art as a tube s'ystemf'and may be ed, with 'a temperature responsiveyapo'r or iliquid irraccordance with the usual practice.

The regulating device also" includes a second jpen'armJZ *car'ryinga stylus "l4 and mechanism foncausing said pen arm; and stylusto makea jrecordon chart49 of the operating and non- "operating condition of the, pump-I3; The vari- 'bllS1idClJfllldOf, the regulating 'device will be set f'io'rth'iinthe course of the description of the operation of thesystem; I j

With this brief description of the apparatus; Tthe invention will bestpbeunderstood by describing the method of controlling the pasteurization nofniilk. starting thesystem in operation, the pu'shbutton switch isfmanually depressed to "complete a circuit for operating the motor- 26 which drives 'pump l3. This circuit may be traced fromone side-0f the alternating'current source, conductors 6| 62, winding of the motor 2 6',- the adjustable rheostat 63 for adjusting the -speed of themo t or, conductors 64, 65, push but? ton switchsprings 40, conductors '66 and 6|, to the other sideofthe alternating current source. lt will be'noted thatth'e' lamp 68, which may be located at any convenient position for-observatibnyis conncted'in multiple with the motor 26 to serve'as anindication that-the motor is oper- "ating-th pum to force milk through the system.

away from the lower end of a baflle, 53.

There is also provided in multiple with these last-described circuits a branch conduit for energizing the solenoid-68 which operates the second pen arm 62. This circuit extends from the conductor 62, conductor 69, winding of the solenoid 68, conductor 10 and thence to conductor 64. By

- providedfwith a stylus '14 which draws a curve in onedirection on the chart 49 due to the action ofjsolenoid 68indicating when the motor and its pump'are started and draws the curve in opposite direction due tospring 19 on the deenergization of solenoid 68 when the'motor and its pump are stopped. a c

It is necessary for the operator to hold the switch 40 closed until such timeas'the temperature of the milk about the bulb 21 in the discharge outlet 2| of the heater reaches the predetermined,

value. -When the milkha-sbeen heated to this temperature, the filling medium in the bulb 21 and the attached tube system causes the'capsular diaphragm;39 to expand which, in turn,,opens the valve 4|. This permits air or. other fluidunder pressure to flow from a pressure-fluid source through the conduit f 42, valve 4I' andthence to the capsular diaphragm-1.43. This diaphragm expands andvby so doing closes the electrical @011? tacts 44 which complete a circuit in shunt of the contactsof the push-button switch 40' so that the circuit for the pump motor, is thus maintained closed automatically as long-as the milkhin the outlet 2| of the milk heater ls cat,

or above, the predetermined temperature. Also when the medium in the-:tube system expands 'ona rise in temperaturmthe :Bourdon spring 31 unwinds and thereby tends, to move ,the link 45 toward the left.- This link which is connected to, the ,pen arm 46 pivotally mounted at 41;;on the frame of the instrument, in turn, moves the .upper end of this pen arm clockwisa'causing its pen or stylus 48 to draw a temperature curve on the graduated chart 49 driven ,inaccordance with,time by a suitable clock motor (not shown) The upper e'nd of the pen arm 46 is connected by a link-50 to theupper endof a baffle-actuating arm 5 I pivoted at 52 in the case.

. V q, T Y q actuating arm when thus moved clockwise, swings bafile pivoted at 54 on a part of the case, is normally forced by theweightl 60 teward a nozzle 55 from which there constantly flows a'fjet'of air or pressure-fluid supplied thereto' from' the supply conduit ,42 through restriction or orifice 56 and conduit 51. As the"temperatureof the milk about, the bulb 2'!- approaches the predetermined value, theBqurddn spring 31 continues to unwind, thereby movingwthe link 45' further toward the left, as shown in Fig. 2. This movement of the link further, swings e upper end ofthe pen arm'46 in a clockwise direction causing the stylus 48 to continue making aitemperature record onchart 49, Theypen arm also causesthe link 50 connected thereto, to swing the lower end of thebaflleactuatingarm 5! toward the left,-as shownl', ,Vilhen the milk'in the outlet 2| of the heater 51s at the predetermined value, the battle-actuatingv arm will begin; to move away from' the baflle v53Fiso;,that the weight 60 attached to theuppertendbf. this-baflle causes the lower end thereof 'to' approach the nozzle- 55.

' This approach of the baffle toward the nozzle results in an increase in pressure in the conduit 51 with the result that the capsular diaphragm 58 expands. The expansion of this diaphragm causes the valve 59 to close when the predetermined temperature is exceeded, thereby shutting oil the flow of pressure fluid from the conduit 42 to the conduit 15. Thus the pressure in the diaphragm top l9w of the valve is relieved and the spring i9c raises the valve disc l9a to permit an increased rate of milk flow through the pipe 29' to the heater 5.

If the temperature of the milk about the bulb 21 in the outlet 2! of the heater drops to the predetermined temperature, then the, Bourdon spring 31 will tend to wind up. This action moves the link 45 toward the right, with the result that the upper ends of the pen arm 46 and the baffle-actuating arm 5! are moved counter-- clockwise. As a result of this movement, the

lower end of the baffle-actuating arm 5| moves" counterclockwise and the pin Ela thereon, swings the baffle 53 away from the nozzle 55. This permits the pressure in conduit 57 to drop, so that the capsular diaphragm 58 collapses slightly to open valve 59. With the valve 59 thus opening, the pressure-fluid flows from the source, through conduits 42 and 15 to the diaphragm top I911. The increased pressure in this diaphragm top moves the valve disc I9d to cover a portion of port lfig so that the rate of fiow through the pipe 29 is reduced. Thus the valve l9 operates under the control of the regulator R to maintain such a flow of milk to the heater that the milk is heated to substantially the exact desired temperature.

If for any reason the temperature of the milk drops below the predetermined value which is unsuitable for pasteurizing purposes, the capsular diaphragm 39 will collapse to close its valve 4|. On this closure of this valve, the capsular diaphragm 43 also collapses to open the contacts 44 in the circuit of the pump motor 26. Thus the motor .26 will immediately stop and the pumping of milk through the system will cease. Since the solenoid 68 operates the pen arm 12 on energization' to swing the pen '14 toward the outer margin of the chart 43 when the pump I3 is being-operated, and since the spring 14 tends to swing this pen toward the center of the chart when the pump is idle, the movement of the pen '14 draws an accurate record on the chart of the 7 periods during which the pump l3 is in operation and also when it is stopped.

Under extremely adverse operating conditions,

it is desirable to replace the valve IS with the dual response regulating unit shown in Fig. 1 of the copending application of Hubbard and Clarridge S. N. 696,650, filed Nov. 4, 1933.

I claim:

1. In a system for heating milk to a predetermined temperature, a heater having a substantially constant heat input, a source of milk to be heated, piping for connectingfsaid source to I said heater, 'meansincluding a pump driven at constant speed for forcing milk through said piping from said source to said heaten a thermosensitive device responsive to the temperature of said milk afterit has been heated, means. in-

eluding a valve'in said piping controlled by said v predetermined value.

2. In a system'fo'r heating milk to a predetermined temperature, a heater having a substantially constant heat input, a source of milk to be arranged always to permit at least a small amount of milk to pass therethrough, and means actuated by said thermosensitive device for stopping said pump Whenever the temperature of the milk at the outlet of said heater drops below a predetermined value. I

RAYMOND E. OLSON. 

